State advantages of short pitch winding over full pitch winding in alternators.
Last Answer : Advantages of Short Pitch Winding over Full Pitch Winding in Alternators: 1) Short pitching reduces the amount of copper needed for end connection when compared with full pitched coil. 2) They ... reduced, thereby increasing the efficiency. 4) The power quality of generated emf is improved.
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May 7, 2020
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anonymous

Last Answer : In the case of lap winding resultant pitch is difference of front and back pitches.
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122 views
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Mar 20, 2018
by
anonymous

A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and front pitch adopted could be respectively
Last Answer : A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and front pitch adopted could be respectively 19,17
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588 views
1 answer
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May 3, 2018
by
anonymous

A _________ is used to measure the stator % winding temperature of the generator. (A) Thermocouple (B) Pyrometer (C) Resistance thermometer (D) Thermometer
Last Answer : A Resistance thermometer is used to measure the stator % winding temperature of the generator.
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3.4k views
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May 8, 2018
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anonymous

Last Answer : The speed control of universal motor used for sewing machines is by varying the resistance.
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105 views
1 answer
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Mar 20, 2018
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anonymous

A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is
Last Answer : A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is 36 Ohm
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May 3, 2018
by
anonymous

Aluminium is not used as winding wire for the armature of a dc machine because (1) aluminium has low resistivity (2) a large winding space is taken by aluminium conductors and creates ... ) the thermal conductivity of aluminium is low (4) aluminium has low conductivity as compared to copper
Last Answer : Aluminium is not used as winding wire for the armature of a dc machine because (2) a large winding space is taken by aluminium conductors and creates jointing problems (3) the thermal conductivity of aluminium is low (4) aluminium has low conductivity as compared to copper
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621 views
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Apr 29, 2018
by
anonymous

In dc machines, the armature windings are placed on the rotor because of the necessity for (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque
Last Answer : 3 Commutation
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291 views
2 answers
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May 1, 2018
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anonymous

Last Answer : In D.C. machines the residual magnetism is of the order of 2 to 3 percent.
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502 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : Most of the fractional horsepower motors have either plain or sleeve bearings.
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92 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : A centrifugal switch is used to disconnect starting winding when motor has picked up about 50 to 70 per cent of rated speed.
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Mar 20, 2018
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anonymous

Last Answer : Sandwich type winding is used in 3 phase shell-type transformer.
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197 views
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Mar 19, 2018
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anonymous

The damping winding in synchronous motor is generally used to?
Last Answer : The damping winding in synchronous motor is generally used to provide starting torque and prevent hunting.
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157 views
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Mar 18, 2018
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anonymous

Silicon steel is used in electrical machines because it has?
Last Answer : Silicon steel is used in electrical machines because it has low hysteresis loss.
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403 views
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Mar 25, 2018
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anonymous

Compare core type transformer and shell type transformer on the following parameters. (i) Types of winding used, (ii) Application
Last Answer : Ans:
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52 views
1 answer
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Jan 8, 2021
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anonymous

Last Answer : In case of D.C. machine winding, number of commutator segments is equal to number of armature coils.
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Mar 20, 2018
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anonymous

Last Answer : Satisfactory commutation of D.C. machines requires brushes should be of proper grade and size, brushes should smoothly run in the holders, smooth, concentric commutator properly undercut.
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106 views
1 answer
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Mar 20, 2018
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anonymous
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Last Answer : Brushes of D.C. machines are made of carbon.
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Mar 20, 2018
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anonymous

Last Answer : Hopkinson's test on D.C. machines is conducted at full-load.
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Mar 20, 2018
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anonymous
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Last Answer : The purpose of retardation test on D.C. shunt machines is to find out stray losses.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : The value of starting capacitor of a fractional horse power motor will be 300 uF .
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1 answer
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Mar 20, 2018
by
anonymous

In a dc machine, interpoles are used to (1) neutralize the effect of armature reaction in the interpolar region (2) generate more induced emf in the armature (3) avoid interference of the armature flux with the main -field flux (4) reduce the demagnetizing effect of armature reaction
Last Answer : In a dc machine, interpoles are used to neutralize the effect of armature reaction in the interpolar region
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175 views
1 answer
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Apr 29, 2018
by
anonymous

Last Answer : Starters are used with D.C. motors because to restrict armature current as there is no back e.m.f. while starting.
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119 views
1 answer
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Mar 20, 2018
by
anonymous

State any two applications of single phase autotransformer.
Last Answer : Applications of single phase auto transformers: 1) Give small boost to distribution cable to correct the voltage drop. 2) As auto transformer starter for induction motors. 3) As furnace supply ... . 5) In control equipment for single phase locomotives. 6) As dimmer in lighting circuits.
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Jan 8, 2021
by
anonymous

State any two conditions for parallel operation of 3-phase transformer.
Last Answer : Conditions for Parallel operation of 3 phase transformer 1) Voltage ratings of both the transformers must be identical. 2) Percentage or p.u. impedance should be equal in magnitude. 3) X/R ratio ... between primary & secondary voltages must be same. 6) Phase sequence on both sides must be same.
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Jan 8, 2021
by
anonymous

Define transformation ratio in terms of current and voltage.
Last Answer : (i) Transformation Ratio (K) is defined as the ratio of the primary current to the secondary current. (ii) Transformation Ratio (K) is defined as the ratio of the secondary voltage to the primary voltage.
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1 answer
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Jan 8, 2021
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anonymous
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Define: (i) Commercial efficiency of a transformer and (ii) All day efficiency of a transformer.
Last Answer : (i) Commercial Efficiency : It is the ratio of output power in watt to the input power in watt. (ii) All day efficiency of a transformer: It is the ratio of output energy in kWh to the input energy in kWh in the 24 hours of the day
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135 views
1 answer
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Jan 8, 2021
by
anonymous

A 50 KVA transformer has iron loss 2 kW on full load. Calculate its iron loss at 75% of full load.
Last Answer : Iron loss is dependent on voltage and independent of load. Hence iron loss at 75% of Load = Iron loss at full load = 2 kW
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104 views
1 answer
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Jan 8, 2021
by
anonymous

State any four properties of Ideal transformer.
Last Answer : Properties of Ideal transformer: 1) No losses (iron and copper losses), hence no temperature rise. 2) No magnetic leakage i.e (Coefficient of coupling between primary and secondary windings is unity) 3) Zero winding ... drop i.e. E1 = V1, E2 = V2 5) Efficiency 100 %. 6) Regulation 0 %.
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1 answer
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Jan 8, 2021
by
anonymous

Draw the connection diagram of long shunt differential D.C. compound generator.
Last Answer : Ans:
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Jan 8, 2021
by
anonymous

How to Pitch in Softball
Last Answer : How to Pitch in Softball They say that in softball, the pitcher is essential, because he is the one who controls the game's pace and the outcome. This is why it's a good idea to know ... when pitching in softball is very important. With these easy steps, mastering this move will be a cinch.
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1 answer

How to Pitch a Tent
Last Answer : How to Pitch a Tent Pitching a tent well means a world's difference between a peaceful sleep outdoors or your tent being blown over by the smallest gust of wind. Here's how to pitch a tent correctly. ... it back as taut as you can. This will help prevent it from flying off should high winds come.
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1 answer

How to Remove Pine Pitch ?
Last Answer : How to Remove Pine Pitch Pine trees are beautiful and elegant, but if you often go near them, you'll find yourself covered with sap dripping from the tree. This is called pine pitch, and can be ... some all over you, just try these easy techniques and you'll get the gunk off quickly and effectively.
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1 answer
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May 9, 2021
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anonymous

Damper winding in a synchronous motor
Last Answer : Damper winding in a synchronous motor Serves to start the motor.
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May 8, 2018
by
anonymous

Damper winding is provided in 3 phase synchronous motors to :
Last Answer : Damper winding is provided in 3 phase synchronous motors to : provide starting torque and prevent hunting
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1 answer
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Apr 29, 2018
by
anonymous

Last Answer : The starting winding of a single-phase motor is placed in stator.
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1 answer
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Mar 20, 2018
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anonymous

Last Answer : If starting winding of a single-phase induction motor is left in the circuit, it will draw excessive current and overheat.
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234 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a magnetic relay.
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215 views
1 answer
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Mar 20, 2018
by
anonymous
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Last Answer : Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.
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222 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The purpose of stator winding in the compensated repulsion motor is to improve power factor and provide better speed regulation.
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110 views
1 answer
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Mar 20, 2018
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anonymous

Last Answer : In split phase motor main winding is of thick wire placed at the bottom of the slots.
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83 views
1 answer
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Mar 20, 2018
by
anonymous

In synchronous motor, does the winding losses vary with load?
Last Answer : No, in the synchronous motor the winding losses do not vary with load.
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512 views
1 answer
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Mar 3, 2018
by
anonymous

The inertia constants of two groups of machines which do not swing together are M1 and M2. The equivalent inertia constant of the system is
Last Answer : The inertia constants of two groups of machines which do not swing together are M1 and M2. The equivalent inertia constant of the system is M1M2/M1+M2
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1.5k views
1 answer
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May 3, 2018
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anonymous

Last Answer : The voltage used for suburban trains in D.C. system is usually 600 to 750 V.
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1 answer
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Mar 22, 2018
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anonymous

Last Answer : D.C. shunt motors are used for driving machine tools.
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1 answer
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Mar 20, 2018
by
anonymous

How is a thyristor used to convert AC to DC?
Last Answer : thyristor
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123 views
1 answer
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Mar 19, 2018
by
anonymous

Which type of starter is used to start the DC motor?
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77 views
0 answers
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Mar 15, 2018
by
anonymous

Why DC motor is used for traction?
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Mar 11, 2018
by
anonymous
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Analyze the differences of FOC and DTC. The switching frequency of FOC is 1.3 kHz and the average switching frequency of DTC is the same.
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0 answers

Can you guys explain the advantages of frequency converter against the star delta or soft starter?
Last Answer : ¬Soft starters A soft starter is, as you would expect, a device which ensures a soft starting of a motor. A softstarter has different characteristics to the other starting ... at rated current from zero to full speed. Frequency converters are becoming cheaper all the time.
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1 answer
